Prior to the present invention various mechanical and adhesive fastener units have been provided to mechanically and adhesively connect parts together. For example in U.S. Pat. No. 3,772,957 issued Nov. 20, 1973 to Albert E Newton for Self-Drilling and Sealing Rivet, the anvil of a blind rivet is provided with a forward drilling head so that it can bore a cylindrical opening for the rivet into parts being joined. This rivet is configured to distribute on-board adhesive into the joint of the parts when the anvil is set so that the parts are mechanically connected and are bonded on adhesive cure. In the U.S. Pat. No. 5,452,977 issued Sep. 26, 1995 to A. S Terrizzi for Fastener System, the threaded shank of a fastener is peripherally channeled to contain separate components of a two-phase bonding material. These components are intermixed when the fastener is installed which bond the fastener to the part being connected. In U.S. Pat. No. 3,472,301 issued Oct. 14, 1969 to M. B Pearce for Self-Sealing Mechanical Fastener, a hex-headed fastener is disclosed which has an externally threaded shank with an axial cavity filled with a viscous sealant. The sealant is distributed into the threaded connection of the shank with an associated internally threaded member to inhibit leakage though the threaded connection.
While these patents disclose an assortment of fastener units that incorporate many commendable features to improve fastening they do not meet new and higher standards for optimized installation and performance for multi-mode mechanical and adhesive fasteners in securing overlapped parts together. The prior units do not disclose or suggest the new and improved torque controlling and adhesive sealing provision of the mechanical and adhesive fastener of this invention. More particularly the prior art does not measure up to the present invention that automatically seals and effectively distributes adhesive under high pressure loads into close fitting joint and interface areas of parts being joined for optimized part bonding as the threaded mechanical connection is being completed with optimized tension.
In further contrast to the prior art, this invention provides a new and improved self-drilling, self-tapping threaded fastener with installation torque automatically controlled by an intermediate sleeve to optimize the mechanical connection of separate parts. This connection is additionally enhanced by the subsequent controlled delivery of onboard adhesives and sealant into the threads of the interconnected members and to the interface of the discrete parts being connected.